JP5168977B2 - Flat panel display - Google Patents

Description

  The present invention relates to a flat display device (flat panel display) using a surface emitting irradiation panel.

  In recent years, flat panel displays such as liquid crystal display panels have been widely used as displays for mobile devices such as mobile phones.

  In order to meet such demands, for example, in liquid crystal display modules, thinning of the glass substrate, which occupies most of the thickness of the module, has been promoted. It has been.

In particular, in a double-sided display module having main and sub liquid crystal display panels used as a display of a cellular phone as shown in Patent Document 1, a glass substrate is required to be thin in order to reduce the thickness of the module. Yes.
JP 2004-87409 A

  However, when the glass substrate of the liquid crystal display panel is made thinner, the mechanical strength such as the bending strength of the entire module is lowered, and there is a problem that it is easily broken when used as a display of a mobile device.

  In particular, in a double-sided display module, the strength of the case is reduced because a display window is provided for each display, and the reduction in mechanical strength due to the thinning of the substrate of each display panel causes cracks in the display panel. It is a factor.

  An object of the present invention is to provide a flat display device that is thinned without reducing mechanical strength.

In the flat display device according to claim 1 of the first invention, a light source is disposed on an end surface of a substantially transparent light guide plate made of tempered glass, and the light source incident from the end surface of the light guide plate the emitted light, and both surface light emitting illumination panel for emitting a planar from the main surface of the both, an optical sheet stack disposed on one of the light emitting surface of the light guide plate, the other light emitting surface of the light guide plate A transflective sheet in which a thin film metal film is formed on one surface of a base sheet including transparent tempered glass that is disposed in contact with the optical sheet, and the optical sheet laminate on one light emitting surface side of the light guide plate a first image display panel disposed opposite via a second image display panel arranged opposite the through semitransparent reflective sheet to the other light emitting surface side of the light guide plate, before Symbol both sides the relative luminescence irradiation panel first image display panel Includes a frame case for holding the preliminary second image display panel is opposed to a predetermined position, and a feature to integrate the said semi-transmitting reflection sheet and the light guide plate by insert molding frame case To do.

According to the flat display device of the reference invention, a flat display device having sufficient mechanical strength can be obtained.

In addition, according to the flat display device of the first invention, it is possible to obtain a flat display device of a double-sided display system in which the image display panel is thinned and the strength is sufficient.

FIG. 1 is a schematic cross-sectional view showing a liquid crystal display module as an embodiment of the reference invention.
The liquid crystal display module of this embodiment is a double-sided display type having display surfaces on both front and back sides of the module, and a main liquid crystal display panel 3 and a sub liquid crystal display sandwiching a surface emitting irradiation panel 2 in a frame case 1 forming a rectangular frame. The panel 4 is arranged so as to overlap with a predetermined distance.

  The frame case 1 is formed by resin molding into a frame having a rectangular planar shape by using, for example, an injection method or the like using a resin material.

  A surface-emitting irradiation panel 2 is disposed at a substantially intermediate portion in the depth direction of the frame case 1. The surface-emitting irradiation panel 2 is a sidelight-type double-sided emission panel. An LED (Light-Emitting Diode) 22 as a point light source is disposed on one end surface of a rectangular transparent light guide plate 21. The optical sheet laminate 23 is installed on the front surface 211 facing the main liquid crystal display panel 3, and the transflective sheet 24 is installed on the rear surface 212 on the opposite side.

  Here, the light guide plate 21 is made of a transparent tempered glass plate. A tempered glass plate is a glass plate that has been processed to withstand bending stress greater than that of normal glass by leaving a strong stress on the glass surface, or by curing the glass surface. There are laws and physical reinforcement methods. A thin glass plate such as the light guide plate 21 of the present embodiment is usually processed by a chemical strengthening method.

  Although not shown, a pair of main surfaces of the light guide plate 21, that is, the front surface 211 and the rear surface 212, are formed with dot patterns for internally reflecting the internally propagated light to the opposite main surface. These dot patterns are formed by applying, for example, a transparent UV (ultraviolet) curable resin as a material by screen printing or the like, and the diameter and distribution density of dots are the main and sub liquid crystal displays to be irradiated. Each of the panels 3 and 4 is set so that planar light can be emitted uniformly.

  In addition, as shown in FIG. 2, a recess 213 for accommodating and installing the LED 22 is formed on the end surface of the light guide plate 21 on the light incident side. In the present embodiment, in order to install two LEDs 22 as a light source, two concave portions 213 are arranged on the light incident side end face of the light guide plate 21 equally to the left and right with respect to the center.

  The light guide plate 21 made of tempered glass formed as described above is insert-molded in the frame case 1. That is, when the frame case 1 is formed, the light guide plate 21 made of tempered glass formed in a predetermined shape is inserted into a predetermined position and formed, thereby forming the light guide plate 21 as shown in FIG. The peripheral part forms an integrally molded product embedded in the depth intermediate part of the frame case 1.

  Thus, the light guide plate 21 made of tempered glass is integrated and installed in the frame case 1 forming the rectangular frame by the insert molding method, so that the light guide plate 21 functions as a reinforcing beam of the frame, and the structure of the frame case 2 Strength increases. As a result, it becomes difficult for the frame case 1 to be deformed by an external force.

  On the front surface 211 of the insert-formed light guide plate 21 facing the main liquid crystal display panel 3, an optical sheet laminate 23 as a light control member is installed. The optical sheet laminate 23 is formed by sequentially laminating a diffusion sheet 231, a first prism sheet 232, and a second prism sheet 233 on the light emitting surface 211. The first and second prism sheets 232 and 233 are each formed by extending protrusions (not shown) having a plurality of cross-sections forming a right triangle extending in parallel at a fine pitch, and the protrusions are orthogonal to each other. It is placed in a superimposed manner.

  An FPC (Flexible Printed Circuit) 25 in which two LEDs 22 are directly mounted by a COF (Chip On Film) method is installed on the light incident side end of the front surface 211 of the light guide plate adjacent to the optical sheet laminate 23. Has been. As shown in FIG. 2, the FPC 25 (hereinafter referred to as “light source FPC”) is attached to the light incident side end in a state where the two LEDs 25 are accommodated and installed in the corresponding recesses 213, and is input side. The end is drawn out of the frame case 1.

  A transflective sheet 24 is attached to the rear surface 212 of the light guide plate 21 that is insert-molded in the frame case 1. The transflective sheet 24 transmits a part of incident light that is emitted to the outside from the rear surface 212 of the light guide plate and reflects the remaining part. In this embodiment, PET (polyethylene terephthalate) or the like is used. The thin film metal film formed on the surface of the transparent base sheet is used.

  On the front side of the double-sided light emitting panel 2 configured as described above, the main liquid crystal display panel 3 is installed at a predetermined interval. The main liquid crystal display panel 3 is formed by joining a pair of rectangular thin glass substrates 31 and 32 with a frame-shaped sealing material (not shown) with a predetermined gap therebetween, and enclosing the glass substrates 31 and 32 surrounded by the frame-shaped sealing material. Liquid crystal is sealed between the opposing surfaces (hereinafter referred to as inner surfaces). A pair of front and rear polarizing plates 33 and 34 are attached to the outer surfaces of the glass substrates 31 and 32, respectively.

  One glass substrate 32 of the glass substrates 31, 32 is formed with a protruding portion 321 by projecting one end portion outside the corresponding end surface of the glass substrate 31. Although not shown in the drawing, the lead wiring that is conductively connected to the electrodes of the substrates 31 and 32, the connection terminals thereof, and the drive signal input wiring are provided on the surface of the projecting portion 321 (extension surface of the electrode forming surface). Etc., and a driver chip 5 as a liquid crystal driving circuit element is mounted by a COG (Chip On Glass) method.

  A flexible wiring board (hereinafter referred to as FPC (Flexible Printed Circuit Board)) 6 for supplying a driving control signal is conductively joined to the connection terminal row of the driving signal input wiring of the protruding portion 321 described above. The FPC 6 is drawn out of the frame case 1.

  A retainer 7 for supporting the sub liquid crystal display panel 4 is fitted and attached to the frame case 1 on the rear surface side of the double-sided light emission irradiation panel 2. The retainer 7 is formed by processing a sheet metal, and has a light irradiation window 71 corresponding to the sub liquid crystal display panel 4 to be supported.

  The sub liquid crystal display panel 4 is obtained by reducing the main liquid crystal display panel 3 to about a half of the plane, and similarly, a pair of glass substrates 41 and 42 are bonded with a liquid crystal sandwiched therebetween, and a glass substrate is obtained. A pair of polarizing plates 43 and 44 are adhered to the outer surfaces of 41 and 42, a driver chip 8 is COG mounted on the substrate protruding portion 421, and an FPC 9 for supplying a drive control signal is provided at the end of the protruding portion. Conductively joined and pulled out of the frame case 1. The sub liquid crystal display panel 4 is fixedly installed on the retainer 7 with an adhesive tape or the like, for example, in an arrangement in which the display area is aligned with the light irradiation window 71 of the retainer 7.

Here, the illumination action in the liquid crystal display module of the present embodiment will be described.
In FIG. 1, the light emitted from the pair of LEDs 22 enters the light guide plate 21 from the opposite end surface portions, propagates while being internally reflected by the front and rear surfaces 211 and 212, and is diffusely reflected by the uneven pattern at that time. To the outside of the light guide plate 21.

  The light that is incident on the rear surface 212, is internally reflected by the uneven pattern, and is emitted from the front surface 211 is transmitted through the optical sheet laminate 233 to become planar illumination light having a uniform luminance distribution and high front luminance, and is a main liquid crystal display panel 3 is irradiated. Of the light incident on the rear surface 212, a part of the light emitted to the outside of the light guide plate 21 is reflected by the transflective sheet 24 that is placed face-to-face and re-entered into the light guide plate 21 to be displayed on the main liquid crystal display. It is used for the irradiation light of the panel 3.

  The light that is incident on the front surface 211, is internally reflected by the uneven pattern, and is emitted from the rear surface 212, is incident on the transflective sheet 24 and part of the light is transmitted. Of the transmitted light and the light that is emitted from the rear surface 212 without being internally reflected and is transmitted through the semi-transmissive reflective sheet 24, the light that has passed through the light irradiation window 71 of the retainer 7 is the irradiation light of the sub liquid crystal display panel 4. Become. The light incident on and reflected by the semi-transmissive reflection sheet 24 is re-incident on the light guide plate 21 and used for the irradiation light of the main liquid crystal display panel 3. A part of the light transmitted through the semi-transmissive reflective sheet 24 and reflected by the retainer 7 without passing through the light irradiation window 71 is transmitted through the semi-transmissive reflective sheet 24 and re-incident on the light guide plate 21. The light is used for the irradiation light of the main liquid crystal display panel 3.

  In this way, the light emitted from the pair of LEDs 22 passes through the concave and convex patterns provided on the front and rear main surfaces 211 and 212 of the light guide plate 21 and the transflective sheet 24, so that both the main and sub liquid crystal display panels 3. 4 are each divided into light quantity ratios necessary for displaying the desired quality, and are irradiated efficiently.

  As described above, according to the liquid crystal display module of this embodiment, the light guide plate 21 of the double-sided light emission irradiation panel 2 is formed of tempered glass, and this is integrated and installed in the frame case 1 forming a rectangular frame by insert molding. Therefore, the structural strength of the frame case 1 having a rectangular frame structure is increased, and the glass substrates of both the main and sub liquid crystal display panels 3 and 4 are thinned despite the fact that they are of the double-sided display type. It is possible to reduce the thickness and ensure sufficient strength.

Next, a liquid crystal display module as an embodiment of the first invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected about the component same as the said embodiment, and the description is abbreviate | omitted.

  The liquid crystal display module shown in FIG. 3 is a double-sided display type similar to the above embodiment, but is made of transparent tempered glass for reinforcing the frame case 10 separately from the light guide plate 301 of the double-sided light emitting irradiation panel 30. A reinforcing plate 20 is provided.

  The frame case 10 is a double box type in which a main storage chamber 101 for storing the main liquid crystal display panel 3 and the double-sided light emission irradiation panel 30 and a sub storage chamber 102 for storing the sub liquid crystal display panel 4 are formed in two layers. I am doing. A communication window 1031 is formed in the partition plate 103 that divides both the main and sub storage chambers 101 and 102.

  At the bottom of the main housing chamber 101, a reinforcing plate 20 made of transparent tempered glass is integrally installed in the frame case 10 by insert molding. Therefore, the peripheral edge of the reinforcing plate 20 is embedded in the bottom side wall of the main storage chamber 101.

  In the double-sided light emission irradiation panel 30, a pair of LEDs 302 are arranged on the end surface of the light guide plate 301 made of a transparent resin such as polycarbonate so that light enters, and the front surface 3011 facing the main liquid crystal display panel 3 of the light guide plate 301 is disposed on the front surface 3011. An optical sheet laminate 303 is installed, and a transflective sheet 304 is installed on the rear surface 3012 on the opposite side.

  The pair of LEDs 302 is housed and installed in a pair of recesses 301 formed on the light incident side end face as in the above embodiment, but the light source FPC 305 on which the LEDs 302 are mounted with COF is light on the rear surface 3012 of the light guide plate. Installed adjacent to the transflective sheet 304 at the incident side end, and conductively connected to the drive liquid crystal control signal supply FPC 6 joined to the main liquid crystal display panel 3 in the frame case 10.

  The transflective sheet 304 of this embodiment is obtained by selectively arranging a reflective film formed by plating or vapor-depositing a metal on a transparent resin film sheet, and the light incident on the reflective film among incident light is reflected by the reflective film. And transmits light incident on the transparent portion between the reflective films.

  As in the optical sheet laminate 23 (see FIG. 1) of the above-described embodiment, the optical sheet laminate 303 includes a diffusion sheet 3031, a first prism sheet 3032, and a second prism sheet 3033 sequentially on the light emitting surface 3011. Layered

  According to the liquid crystal display module of the present embodiment configured as described above, a transparent tempered glass plate is inserted separately from the light guide plate 301 as the reinforcing plate 20 for reinforcing the frame case 10 of the double-sided display type liquid crystal display module. Since the frame case 10 is integrally installed by the molding method, the structural strength of the frame case 10 can be increased without using a special light guide plate made of tempered glass as in the above embodiment. As a result, it is possible to easily obtain a double-sided display type liquid crystal display module that is thin and has sufficient structural strength by using the resin light guide plate 301 having a desired optical function.

The present invention is not limited to the above embodiment.
For example, instead of the transflective sheet 24 in the embodiment shown in FIG. 1, as shown in FIG. 4, a thin metal film 402 is vapor-deposited on one surface of a base sheet 401 made of transparent thin tempered glass. The transflective sheet 40 may be used and the transflective sheet 40 and the light guide plate 21 made of tempered glass may be integrated with the frame case 50 by insert molding. The frame case 50 in this case can be formed in a double box shape like the frame case 10 in the embodiment shown in FIG. As a result, the structural strength of the frame case 50 is further increased by the integrated reinforcing beam made of the double tempered glass made of the light guide plate 21 and the semi-transmissive reflective sheet 40 and the double box structure, and the thinning is promoted and the structure is enhanced. Thus, a more robust double-sided display type liquid crystal display module can be obtained.

  Further, the structure of the first invention, that is, the structure in which the light guide plate made of tempered glass is insert-molded in the frame case is not limited to the double-sided display type flat display device, but is also effectively applied to a normal single-sided display type flat display device. Is possible.

  In addition, both the first and second inventions are not limited to the case where the image display panel is a liquid crystal display panel, and can be widely applied to other flat display devices other than a liquid crystal display device using a surface emitting irradiation panel as a light source. Of course.

It is a typical sectional view showing a liquid crystal display module as one embodiment of a reference invention. (A) is a fragmentary perspective view which shows the structure of the specific part in the said liquid crystal display module, (b) is a top view which shows the installation state of the said specific part. It is a typical sectional view showing a liquid crystal display module as one embodiment of the 1st invention. It is typical sectional drawing which shows other embodiment of this invention.

Explanation of symbols

1 Frame case (rectangular frame type)
2 Double-sided light emitting panel 21 Light guide plate (made of tempered glass)
3 Main liquid crystal display panel 4 Sub liquid crystal display panel 5, 8 Driver chip 6, 9 FPC (for driving control signal supply)
7 Retainer 10 Frame case (double box type)
20 Reinforcing plate 30 Double-sided light emitting panel 301 Light guide plate (transparent resin)
40 Transflective sheet 401 Base sheet (made of transparent tempered glass)
402 thin metal target film

Claims (1)

Light source is disposed on the end face of the substantially transparent light guide plate made of tempered glass, both sides to emit light emitted from the light source which enters from the end face of the light guide plate, the surface shape from the main surface of both A luminescent panel;
An optical sheet laminate disposed on one light exit surface of the light guide plate;
A transflective sheet that is disposed in contact with the other light exit surface of the light guide plate, and a thin metal film is formed on one surface of a base sheet containing transparent tempered glass;
A first image display panel disposed opposite to the light output surface side of the light guide plate via the optical sheet laminate;
A second image display panel disposed opposite to the other light exit surface side of the light guide plate via the transflective sheet;
A frame case which holds so as to face the first image display panel and the second image display panel of a predetermined position relative to the front Symbol both surface emitting radiation panel,
Have
A flat display device , wherein the transflective sheet and the light guide plate are integrated by insert molding into a frame case .

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